A Comparative Study of the Physical and Biological Properties of Commercially-Available Binders for Shrimp Feeds

Abstract

In accordance with binder manufacturers' recommendations, commercial binders were added to a standard control feed to create twelve binder treatments. These binder treatments and their controls were processed under standard conditions to determine if the binders could improve the stability of a shrimp feed. To make that determination, pellets processed with the added binder treatment were compared with their control (no binder), after being immersed in water for four time periods (30, 60, 120, and 240 minutes) and compared for pellet structure and nutrient leaching (crude protein, lipid, and ash). Hydro-Gard and Compact-PBX were the only two binders that showed significant (P< 0.05) improvement in pellet structure over their controls in all four time periods. From the pellet structure data, the binders were ranked from the most to the least stable as follows: Maxi-Bond H20, Agrimer Mix, Maxi-Bond, Pell-Tuff, Compact-PBX, Hydro-Gard, Biodone AQ90, Carbo Binder, A.MAS, Pro Blend, Aqua-Tec “N,” and Nutri-Binder. All binders were ranked according to the amount of protein retention after the four leaching periods. The leaching data for protein showed a general trend toward higher protein retention in diets containing binders, compared to their controls. Protein remaining in the leached pellets was especially evident in the urea formaldehyde binders (Compact-PBX and Maxi-Bond) and in the natural and hydrophilic polymers (Hydro-Gard). These binders retained significantly (P <0.05) more protein than their controls in all time periods. The binders were ranked from the greatest amount of protein retained to the least protein retained, as follows: Maxi-Bond, Maxi-Bond H20, Pell-Tuff, Compact-PBX, Agrimer Mix, Hydro-Gard, Carbo Binder, Aqua-Tec “N,” A.MAS, Biodone AQ90, Pro Blend, and Nutri-Binder. The binders were also tested for pellet durability index (PDI), pellet hardness, pelleting efficiency, and the cost of binder inclusion per metric ton of feed. There were no significant differences (P >0.05) in pellet hardness and pelleting efficiency among all binders tested. The least expensive binder was a urea-formaldehyde binder (A.MAS), which cost $4.41 per ton of feed. Agrimer Mix and Biodone AQ90 were ranked the top binders for PDI and were significantly (P <0.05) more durable than Nutri-Binder but not significantly (P >0.05) different from all other binders. Shrimp average final weight (g) at eight weeks for Pro-Blend (7.80), Carbo Binder (7.52), Agrimer Mix (7.50), Biodone AQ90 (7.33), and the control (7.27) ranked first through fifth for growth. Shrimp fed binders containing urea-formaldehyde, Maxi-Bond, Compact-PBX, and Pell-Tuff, when added above 0.5% reduced shrimp final weights and weekly growth. Shrimp survival in this trial was very high (100-91.7%) and there were no significant (P >0.05) differences among treatments for survival. Feed Conversion Ratios (FCR) ranged from Pro-Blend (1.46:1) to Pell-Tuff (2.12:1) where these two treatments were significantly (P <0.05) different from each other.